Closed-type rotary hydraulic system for crane and crane

Abstract

The invention discloses a closed-type rotary hydraulic system for a crane. The system comprises a closed-type hydraulic pump (10) and a rotary motor (20), wherein an oil outlet of the closed-type hydraulic pump (10) is connected with an oil inlet of the rotary motor (20); and an oil outlet of the rotary motor (20) is connected with an oil inlet of the closed-type hydraulic pump (10). The system is characterized by further comprising a buffering damper (30), and the buffering damper (30) is connected in parallel with the rotary motor (20) on a hydraulic oil line. The system has very reliable stability in the starting, stopping and rotating processes, and also has a smaller hydraulic structure. The invention also discloses a crane which is provided with the closed-type rotary hydraulic system.

Description

technical field [0001] The invention relates to the technical field of engineering machinery, in particular to a closed rotary hydraulic system of a crane. The invention also relates to a crane provided with said closed slewing hydraulic system. Background technique [0002] A crane is a kind of construction machinery that uses a boom to lift heavy objects during work, and then relies on the turntable to rotate the heavy objects from one position to another. [0003] The slewing mechanism is a device for the slewing part of the crane to realize slewing motion relative to the non-swinging part. The function of the slewing mechanism is to make the upper part of the car rotate around the slewing center of the crane, and connect the upper car and the lower car in the form of rolling support. Integral, so that the load on the vehicle is transmitted to the chassis frame, and its dynamic characteristics directly affect the working characteristics of the entire crane. [0004] The...

AI Technical Summary

Problems solved by technology

[0014] The closed system realizes the stable control of the rotation through the closed variable variable pump and the two-speed valve group. Although it can meet the requirements of the crane to a certain extent, there are still certain impacts during the start, stop and rotation process, and it cannot Avoid instantaneous impact caused by load mutation

[0015] In addition, the closed system is too complicated, and the number of hydraulic pipelines and control components is too large. Not only the manufacturing cost is high, but also the maintenance is difficult. There may be many fault points, and the probability of rotation fault is relatively high. When performing free sliding, it is necessary to operate multiple control valves to coordinate actions, which puts forward higher requirements for operators

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